Continuous-heating furnace



vVb. 5% FETC- coNTNUoUs HEATING FURMACE -Filed CZ. l, 1923 Sem. 1, 'w25 N @A www 9 w A UNITED- STATES WILLIAM HENRY FITCH, OFA'LLENTOWN, PENNSYILVANIA.

conrmuousnnerme nommen.

Application filed `October 1, 1923. Serial `665,956.

f To all whom t may concern.'

Be it known that l, VILLIAM HENRY FITCH, a citizen of the United States, residing at Allentown. in the county of Lehiglu State of Pennsylvania, have invented certain new and useful Improvements in Coutinuous-Heating Furnaces; and l do hereby declare the following to vhc afull, clear, and exact description of the invention4` such :is will enable others skilled intheart to which it appertains to make and use the same.

This invention relates to continuous heat` ing furnaces and `has for its object the provision of certain improvemeiits'in furnaces of this type whereby a .finely divided Acai;-

bonaceousfuel, such as pulverized coal. may be successfully employed. t

Heretofore pulveried coal` or other finely divided carbonaccous material. has been used 2 0 as a fuel in {ii-ing continuouslieatiug furnaces' although the refuse ,depositing iii the furnace durinfrt-he combustion of thc. coal very materially hampered its iluost successful operation. The yditlicultiesI encountered iii the use of pulverized coal with a very lov ash content may be partially overcome in some instances, but thc use of a coal o f high Aash content' heretofore has `lcd to very unsatisfactory results7 due to the necessity `of stopping operation ot the furnace for clean ing out slag'. This results in much labor and naturally interferes with the quantity of steel rolled.

The disposition of ash is more or less ofka problem according to the ash contentotthe coal used. The factors which must be considered are the meltinei point of the ash` the quantity of ash entering the furnace in a given time, and the manner in which the i0 coal is prepared and applied to the furnace, While all the ash in the coal is proiected into the furnace, only a. comparatively small percentage .of the ashy is precipitated in molten form, the quantity deposited in a days time usually being sufficient to cause its removal to be necessary `in a continuous :heating furnace of the type employed for heating billets of metal for rollingandthe like; the major portion being deposited '50 throughout the furnace hearth and tlues in the form of dust. f

The present invention contemplates cer* tain improvements in the construction of a continuous heating furnace particularly 5 5 adapted for the use of pulverized coal as a fvided for displacing refuse deposi Y Nether parts of the furnace. For example,"

fuel* 'and-theprovision of means for overcoming detrimental effects due to deposited refuse in the `furnace; The 'furnace con-- struction of the invention includes a chamber in close proximity to the combustion region for collecting and trapping refuse formed during combustion of the fuel.A Preferably, this chamber is providedlwith -au easily removable bottomportion which' may bc removed and replaced by another similar portion during the operation of the' furnace. Additional means mayslhel" mi one` or more openings may be provided throughout the` length ofthe furnace to perul mit the insertion of a cleaning iron or the like for displacingr deposited refuse.' Both liquid and dust ash may be removed Without interference to further operation in aproperlv designed and operated furnace."-f`

vThe furnace construction ofthe invention permits the maximum circulation of the hot gases around the material to he heatedparticularly in the region of high temperatures, thereby insuring the uniform heating'ofl the material before beingl ejected from the furnace.` For example the rails traversing-the furnace for guiding material to he heated through the furnace may be supported by `a frame composed of hollowY members to permit the passage therethrough of -a cooling fluid` such as Water or air. may be hollow-to 4permit the passage therethrough of a cooling;` fluid. f l f Up to the present time practically all conti nuous heating furnaces have employed produrer gas, Yor gasified'coal as fuel; For this reason they have been constructed with recuperators for preheating of air for combustion. This is necessaryv Where` coal is tion and the operating cost of afurnaee'embodying the present invention isfverygmch less than th at of former general practice. I

The rails also .frasi tied in order to produce the desired "flame have operated/,a furnace of this construction y with a fuel consumption as low as 90 pounds the charge.

of pulverized coal per ton of billets heated. The fuel consumption, however, will vary slightly with the temperature and weight of These and other features of the invention :will be more clearly understood by reference to the following description in conjunction with the accompanying drawings; in which- A Fig. 1 is a. sectional elevational view of a furnace embodying the invention; aud

Fig. 2 is a plan view in section taken along the line 2-2 of Fig. 1.

A continuous heating,r furnace compris ing a floor 6, side walls 7. end walls S and and a top or roof of appropriate refractory material is supported at asuitable height by columns 1l of any-structural ma-l terial, such as brick or steel. Guiding` rails 12 of a. track traverse the interior of the furnace and serve to guide material to be heated through the furnace. `The rails 12 are preferably hollow and communicate at one end with an inlet pipe 13 for supplying a cooling fluid, such as water or air. the other end leading to an outlet pine 14' secured to one of the support-ing columns 11. A platform 15 is provided at the charging end of the furnace for holding a supply of billets, or other material to behheated, from which they are forced through the furnace by any appropriate means, such for example as a hydraulic ram 16, and are discharged from the other end through a hinged door 1'? on to a conveyor 18 for transfer to the mill. Y

The guiding rails 12 may 'be supported within the furnace 4by refractory blocks 19. But in the region of high temperature l'. provide a supporting frame composed of hollow cross members supported by the side walls 7 of the furnace, and communieating at one 'end with an inlet pipe 21 for supplying a' cooling fluid, such as water or air, the other end communicating with an outlet. pipe The cross members 20 of the supp tino frame rest upon a. longitu* dinally mscd hollow supporting member 23 communicating: at one end with a cooling fluid pipe 24, supported in a column 11, and. at the other end With the outlet pipe 14.. This'construction permits the free circulation of the hot gases in the region of high temperature around the material to be heated.

1i. burner 25 is provided in the end Wall 8 of the furnace, and is adapted forsupply ing a finely divided coal and airto the furnace for combustion. An opening 26 in 'the floor tl of the furnace leads to a chamber for collecting.:1 and trappingrefuse' formed during combustion of the fuel. This chamber maybomprise a car. 2T placed below the openiniq 26 so as to maire la substantially air tight connection. rlhe side walls .7 contain a plurality of openings or apertures 28, which normally are closed but which may be opened at any time during the operation of the furnace to permit the insertion of a cleaning ironv for displacing dust.

A flue 29 adjacent the end Wall 9 of the furnace leads to the stack, and is provided with an opening 30 normally closed by a door 31. The opening 30 leads to a chamber 32 to provide room for the operator to clean the stack fines.

The furnace is brought to a suliciently high temperature and maintained by the combustion of suitably prepared pulverized coal injected through the burner 25 together with an appropriate supply of air, or other combustion supporting gas. Materialto be heated is then charged into the furnace from the platform 15 by the ram 16, and is heated to the desired temperature by progressive passage along;- the rails l2 to the opposite end of the furnace where it is dis# charged through the door 17 into .a `conveypr 13 for transfer to another part of the mil @tiring combustion of the coal considerable molten and powdered refuse ash may be formed; substantially all the molten ash and a large portion of the powdered ash settles and is collected and trapped in the chamber or car 27; other portions being,r precipitated throughout the furnace from the hot gases While passing through the furnace to thestack. The apertures or openings 28, which are normally closed, may be opened at any -time to permit the insertion of a cleaning iron, or the like, for removing refuse depositing in the furnace. If the stack ilues become burdened with refuse to an objectionable extent the operator may gain access thereto at any time through the opening 30 and door 31 leading from the chamber 32.

While the furnace is in operation, a fiow of cooling' Huid, such as water or air, is maintained through the rails 12, and through the hollow members 2O and 23 of the supporting frame. The supporting frame is so positioned in the furnace as to permit the gases of highest temperature to circulate freely around the material being heated so as to insure! the uniform heating of the material in the furnace. Generally, the supporting frame spans the opening 26 to the chamber or car 27 because the refuse collecting car 27 is usually positioned adjacent the combustion zone or region of hi gzhest temperature.

-I claim:

Y ,1. A continuous heating furnace comprising .aheating chamber, a combustion chamber-adapted for burning pulverized fuel, means operatively associated With the combustion chamber forV collecting and trapping refuse vformed during combustion of the fuel, said means forming a portion of the bottom of the combustion chamber and being adapted for easy removal.

2. A continuous heating furnace comprising a heating chamber, a combustion chamber adapted for burning pulverized fuel, a large Opening in the bottom of the furnace, and a removable car adapted to close said opening, saidy opening and said oar being So positioned in the bottom of the furnace as to collect and trap a relatively large portion of the refusel formed during combustion of the fuel.

v3. A continuous heating furnace comprising a heating chamber, a combustion chamber adapted for burning pulverized fuel, means operatively associated with the' combustion chamber for collecting and trapping refuse formed duringcombustion of the fuel,` said means forming a portion of the bottom of the combustion chamber and being adapted for easy removal, and means permitting removal 'of refuse deposited in the heating chamber.

4. A continuous heating furnace comprising a heating chamber, a combustion chamber adapted for the burning of pulverized fuel, and a chamber in close proximity to the combustion region for collecting and trappinof refuse Aformed during combustion of the fuel, said chamber having an easily removable bottom portion. i

5. AA continuous heating furnace comprising aA lieatin 'chamber,-a combustion chamber adapted 'ftirthe burning of pulverized fuel,l a track in the heating chamber for guiding material to be heated, a supporting frame for the track traversing the region of high temperature Within the heating chamber to permit the free circulation of hot gases around the material to be heated. said track and frame being vcomposed of hollow members to permit the ioW therethrough of a cooling'tluid, and a chamberbcloiv the region of high temperature of the heating chamber for collecting and trapping refuse formed during combustion of the fuel, said chamber having an easily removable bottom portion.

6. A continuous heating furnace compris ing a heating chamber, a combustion chamber adapted for the burning of pulverized fuel, a track in the heating chamber for guiding material to be heated, a supporting frame for the track traversing the region of high temperature Within the heating chamber to permit the free circulation of hot gases around the material to be heated, said track and frame being composed of hollow members to permit the flow therethrough of a cooling fluid, a chamber below the region of high temperature of the heating chamber for collecting and trapping refuse formed during the combustion of the fuel, said chamber having `an easily ree movable bottom portion, and means permitting the removal of refuse deposited. in the 'heating chamber.

In testimony whereof I aflix my signature."

WltLLIAM HENRY FITCH. 

